1. Field of the Invention
The present invention relates generally to a method and an apparatus for transmitting and receiving control information in a broadcasting/communication system, and more particularly, to a method and an apparatus for transmitting and receiving the control information in the broadcasting/communication system using a Low Density Parity Check (LDPC) code.
2. Description of the Related Art
FIG. 1 illustrates a frame used in a conventional broadcasting/communication system.
Referring to FIG. 1, a frame 101 including control information is transmitted and received in a broadcasting/communication system. The frame 101 includes a preamble 102, Layer 1 (L1) signaling 103, and data 104. Herein, the control information can be transmitted in the preamble 102 and the L1 signaling 103. The preamble 102 is a signal used to acquire time and frequency synchronization, frame boundary synchronization, etc., of a receiver.
As illustrated in FIG. 1, the data 104 includes Physical Layer Pipes (PLPs) 108, 109, and 110. Different modulation schemes and code rates can be independently used for PLPs, respectively.
The L1 signaling 103 indicates where an L1 signal is transmitted, and includes L1-pre information 105, L1 configurable information 106, and L1 dynamic information 107. The L1 configurable information 106 and the L1 dynamic information 107 are referred to as L1-post signaling information 120. Also, the L1 configurable information 106 may be referred to as configurable L1-post signaling, and the L1 dynamic information 107 may be referred to as dynamic L1-post signaling.
The L1-pre information 105 includes information that rarely changes in the time domain, such as a cell identifier, a network identifier, the number of radio frequencies, the length of frames, and the position of a pilot subcarrier. The L1 configurable information 106 includes information that changes more often than the L1-pre information 105. Examples of the L1 configurable information 106 include a PLP identifier, a modulation scheme employed to transmit each PLP, and code rate information.
In FIG. 1, the L1 dynamic information 107 includes information that may change in each frame, such as information on a position at which each PLP transmitting service data is transmitted in a current frame (i.e., information on positions at which each PLP transmitting service data starts and ends in a current frame).
Additionally, the L1-post signaling information 120 may include information other than the L1 post configurable information 106 and the dynamic information 107. For example, the L1-post signaling information 120 may include extension information, a Cyclic Redundancy Check (CRC), which is an error check code, and L1 padding. For example, use of the CRC has been described in “Peterson, W. W. and Brown, D. T. (January 1961). “Cyclic Codes for Error Detection” Proceedings of the IRE 49: 228. doi:10.1109/JRPROC.1961.287814.”
The PLP 1 108, the PLP 2 109, and the PLP N 110 are service data, each of which transmits at least one broadcasting service channel. The PLP 1 108, the PLP 2 109, and the PLP N 110 include the actual broadcast data.
Referring to FIG. 1, a receiver that has acquired synchronization of the frame 101 through the preamble 102, obtains information including a scheme in which data is transmitted, the length of frames, etc., through the L1 signaling information 103. The receiver then receives the relevant data through the PLPs 108 to 110 based on the obtained information.
As described above, when control information such as signaling information is transmitted in the broadcasting/communication system, the performance of encoding of the control information must be better than the performance of encoding of data information. Therefore, there is a need for an efficient encoding method of the signaling information and an efficient decoding method thereof.